Numerous attempts have been made to develop covers or protective devices for combination locks utilized with safes and drawers. These are desirable to limit or inhibit a thief's access to the dial or the lock mechanisms utilized with the dial.
According to Federal Specification AA-F-358H, access to a combination lock may be gained by pulling out the dial assembly which is held in place with a snap ring. Removal of the dial assembly provides access to the screws that mount the dial ring assembly on the door. Thus, after removal of the snap ring then dial ring assembly through said screws, access to the interior of the enclosure may be obtained by drilling through the safe or cabinet door behind the dial ring after such removal. After access, the dial ring may and spindle assembly may be replaced without visual indication of tampering or access. Accordingly, a brief visual inspection does not immediately reveal that a break-in or breach has occurred. It would be preferable that a brief visual inspection of the drawer would immediately indicate that a breach of security has occurred.
The prior art combination lock drawers have utilized welded plates to cover portions of the combination lock structure. Covering portions of the combination lock inhibits tampering with the lock in order to inappropriately access contents of the safe. Unfortunately, when welding hard face material, which typically contains tungsten carbide chips, directly to the front of the lock or safe door, the welding can distort the box and inhibit lock installation or proper operation. While these types of plates prolong entry to the cabinet, they often do not prohibit entry.
According to time limitations of the Federal Specification, the only alternative would be cut lock bolts by cutting through the lock door of the safe or cabinet and replacing with a new front door or drawer and new lock bolts. This is much more labor intensive and fails to meet the time restrictions of the Federal Specification.
It would be highly desirable to develop a combination lock protector which requires such activity that access to the combination lock fails to meet time restrictions of the federal guidelines. It would also be highly desirable to inhibit non-visible entry of the safe or drawer, so that tampering indication is clearly evident upon a brief or preliminary visual inspection of the drawer or safe.